The exact cause of some diseases is unknown, but scientists believe they run in families. This supports the idea that they are genetic disorders, but the underlying cause has not been identified.
Link your page to this one if your sources specifically say the exact cause is unknown. Do not link to this page if the cause is unknown to just you.
Link your page to this one if your sources specifically say the exact cause is unknown. Do not link to this page if the cause is unknown to just you.